Abstract We have already more than X hundreds wells!! We do not need a seismic cube now, do we????? Who has not heard that kind of exclamation/question while working in oil/gas field development?? Casabe oil field was not the exception. Discovered in 1941, it's been in production since 1945. It cumulated 297 MM bbl of oil (October 2008) with more than 1100 wells drilled. Since 2004, it's been operated by an Alliance formed by Ecopetrol and Schlumberger. A 3D seismic cube was shot during the first half of 2007. By the middle of 2008, the seismic cube had been loaded and interpreted and by October of 2008 the production had been boosted more than 50%. The reasons….?. Two main reasons: Seismic cube dataSelective string water injection Of course: The second can not be properly implemented without the first. By having a 3D seismic cube we were able to: Develop a precise and reliable structural modelDefine more accuratelly W/O contactsDefine more accuratelly the size of the fieldDesign more accurately well trajectoriesProperly place injector/producer wellsDesign more accurately the injection patternsEstimate reservoir quality: Seismic Inversion dataCompute gas reserves: Attribute-AVO analysisIncorporate undeveloped areasDiscover a new prospect In other words it was possible to: Get more precise reserve picturesIncorporate: 10 % of the OOIP